As some one who just went through the decision making process and ended up with a 2009 370Z base w/ Sport Package M6. I had a hard decision myself and was shopping against an 06-08 BMW M Coupe. There are many things that help me choose cars that I buy but one that always stands out is HERITAGE! I Choose cars and manufacturers that have history and seem to share the same enthusiasm to make cars as I have to buy them. I don't get that feeling when I hear Hyundai Genesis. Now this wasn't the case for all my purchases some choices have to be made for other reasons...I'm talking to you chevy cobalt and colorado...But even my first Laser was part of something. Not saying Hyundai won't get there, it's just not there now. What made me choose the Z over the M was I hated the interior of the M Coupe but loved the exterior and loved the performance but not the drivability.
To me the Z was the complete package. And I think the same could be said about it going against the Genesis.